seaweedfs/weed/filer/cassandra_store/cassandra_store.go
2016-11-28 20:07:27 -08:00

97 lines
2.5 KiB
Go

package cassandra_store
import (
"fmt"
"strings"
"github.com/chrislusf/seaweedfs/weed/filer"
"github.com/chrislusf/seaweedfs/weed/glog"
"github.com/gocql/gocql"
)
/*
Basically you need a table just like this:
CREATE TABLE seaweed_files (
path varchar,
fids list<varchar>,
PRIMARY KEY (path)
);
Need to match flat_namespace.FlatNamespaceStore interface
Put(fullFileName string, fid string) (err error)
Get(fullFileName string) (fid string, err error)
Delete(fullFileName string) (fid string, err error)
*/
type CassandraStore struct {
cluster *gocql.ClusterConfig
session *gocql.Session
}
func NewCassandraStore(keyspace string, hosts string) (c *CassandraStore, err error) {
c = &CassandraStore{}
s := strings.Split(hosts, ",")
if len(s) == 1 {
glog.V(2).Info("Only one cassandra node to connect! A cluster is Recommended! Now using:", string(hosts))
c.cluster = gocql.NewCluster(hosts)
} else if len(s) > 1 {
c.cluster = gocql.NewCluster(s...)
}
c.cluster.Keyspace = keyspace
c.cluster.Consistency = gocql.Quorum
c.session, err = c.cluster.CreateSession()
if err != nil {
glog.V(0).Infof("Failed to open cassandra store, hosts %v, keyspace %s", hosts, keyspace)
}
return
}
func (c *CassandraStore) Put(fullFileName string, fid string) (err error) {
var input []string
input = append(input, fid)
if err := c.session.Query(
`INSERT INTO seaweed_files (path, fids) VALUES (?, ?)`,
fullFileName, input).Exec(); err != nil {
glog.V(0).Infof("Failed to save file %s with id %s: %v", fullFileName, fid, err)
return err
}
return nil
}
func (c *CassandraStore) Get(fullFileName string) (fid string, err error) {
var output []string
if err := c.session.Query(
`select fids FROM seaweed_files WHERE path = ? LIMIT 1`,
fullFileName).Consistency(gocql.One).Scan(&output); err != nil {
if err != gocql.ErrNotFound {
glog.V(0).Infof("Failed to find file %s: %v", fullFileName, fid, err)
return "", filer.ErrNotFound
}
}
if len(output) == 0 {
return "", fmt.Errorf("No file id found for %s", fullFileName)
}
return output[0], nil
}
// Currently the fid is not returned
func (c *CassandraStore) Delete(fullFileName string) (err error) {
if err := c.session.Query(
`DELETE FROM seaweed_files WHERE path = ?`,
fullFileName).Exec(); err != nil {
if err != gocql.ErrNotFound {
glog.V(0).Infof("Failed to delete file %s: %v", fullFileName, err)
}
return err
}
return nil
}
func (c *CassandraStore) Close() {
if c.session != nil {
c.session.Close()
}
}